Inhibitory effects of ethyl pyruvate on platelet aggregation and phosphatidylserine exposure

The anticoagulant effects of ethyl pyruvate in whole blood samples

BACKGROUND

Ethyl pyruvate (EP), the ethyl ester of pyruvate, has proven antiinflammatory and antioxidative properties. Additionally, anticoagulant properties have been suggested recently. EP, therefore, is a potentially antiatherosclerotic drug. We aimed to investigate whether EP possesses antiplatelet and anticoagulant properties particularly in the physiological environment of whole blood.

METHODS

We investigated the effects of increasing concentrations of EP on platelet function, on the course of clot development, and on standard coagulation times. Additionally, clot ultrastructure using scanning electron microscopy was analysed.

RESULTS

EP exerted significant antiplatelet actions: i) Impedance aggregometry amplitudes (11.7 ± 3.0 ohm, 0 μg/mL EP) dose dependently decreased (7.8 ± 3.1 ohm, 1000 μg/mL EP; -33.3%). ATP exocytosis (0.87 ± 0.24 nM, 0 μg/mL EP) measured by the luminiscent method dose-dependently decreased (0.56 ± 0.14 nM, 1000 μg/mL; -35.6%). ii) Closure times (104.4 ± 23.8 s, 0 μg/mL EP) using the Platelet function analyzer were dose-dependently prolonged (180.5 ± 82.5 s, 1000 μg/mL EP; +72.9%) using membranes coated with collagen/ADP. iii) Surface coverage (15.9 ± 5.1%, 0 μg/mL EP) dose-dependently decreased (9.0 ± 3.7%, 1000 μg/mL EP; -43.4%) using the Cone and Platelet analyzer. EP also exerted significant anticoagulant actions: Coagulation times (177.9 ± 37.8, 0 μg/mL EP) evaluated by means of thrombelastometry were dose-dependently prolonged (212.8 ± 57.7 s, 1000 μg/mL EP; +19.6%). Activated partial thromboplastin times (31.5 ± 1.8 s, 0 μg/mL EP) were dose-dependently prolonged (35.6 ± 2.3 s, 1000 μg/mL EP; +13.0%). Prothrombin times (0.94 ± 0.02 INR, 0 μg/mL EP) were dose-dependently prolonged (1.09 ± 0.04 INR, 1000 μg/mL EP; +16.0%).

CONCLUSION

We found that EP possesses antiplatelet and anticoagulant properties in whole blood. Together with its proven anti-inflammatory and antioxidative properties, EP is a potentially antiatherogenic drug.

Reduction of thrombotic and inflammatory complications of polystyrene-block-polyisoprene-block-polystyrene (SIS) with one-step electrospinning

Polystyrene-block-polyisoprene-block-polystyrene (SIS) has been used as biomaterials due to its soft and stable properties under physiological conditions. However, the thrombotic and inflammatory complications caused by SIS restrain its application as blood-contacting implant. To overcome this problem, the hydrophilic core-shell structured SIS-based microfiber with antioxidant encapsulation is fabricated with one-step reactive electrospinning. We demonstrate that the phase separation of SIS and acylated Pluronic F127 (F127-DA) components and crosslinking during electrospinning renders the microfiber blood compatible and stable under physiological condition; the encapsulation of 2-O-d-glucopyranosyl-l-ascorbic acid (AA-2G) in microfiber and subsequent release of AA-2G detoxifies the excess reactive oxygen species (ROS). The microfibers are nontoxic to cells and promote the fast growth and proliferation of human umbilical vein endothelial cells (HUVECs) in the presence of ROS; the thrombotic and inflammatory complications are effectively reduced with implant evaluation in vivo. Therefore, our work paves a new way to improve the biocompatibility of SIS, making it a promising candidate for blood contact materials.

Ethyl pyruvate and analogs as potential treatments for acute pancreatitis: A review of in vitro and in vivo studies

Ethyl pyruvate (EP) has been shown to improve outcomes from multiple organ dysfunction syndrome (MODS) in experimental animal models of critical illness. This review aimed to summarise in vitro and in vivo effects of EP analogs on acute pancreatitis (AP) with the objective of proposing medicinal chemistry modifications of EP for future research. In vitro studies showed that both sodium pyruvate and EP significantly reduced pancreatic acinar necrotic cell death pathway activation induced by multiple pancreatic toxins. In vivo studies using different murine AP models showed that EP (usually at a dose of 40 mg/kg every 6 h) consistently reduced pain, markers of pancreatic injury, systemic inflammation and MODS. There was also a significant increase in survival rate, even when EP was administered 12 h after disease induction (compared with untreated groups or those treated with Ringer's lactate solution). Experimental studies suggest that EP and analogs are promising drug candidates for treating AP. EP or analogs can undergo medicinal chemistry modifications to improve its stability and deliverability. EP or analogs could be evaluated as a supplement to intravenous fluid therapy in AP.